Originally posted by macula56 nice looking stuff Normster. if you don't mind me asking, what schematic are you working off of? jmac

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It's basically the '77 Hybrid-A schematic with a tube reverb circuit added in place of the effects loop. Channel switching will be done via a Weber low power board. Tone stack switches will include a 500pF to 250pF treble cap switch, boost switch, and possibly a combination bright/deep switch.

memphisrain - The diagram is in Visio format. Shoot me an email (nfeaster <at> comcast.net) and I'll mail it to you. It's not completely accurate so you'll have to use the Hybrid-A schematic on blueguitar.org to verify the switch connections.

Gary - Your site has been a major inspiration for me. I especially like the way you mounted the relays to the board...makes for short elegant connections to critical tone circuits. This time around I'm just using a Weber channel switch board, but as you can see, I left plenty of room on the board for relays.

The tweaks are mostly in the tone stack area. I'm going to be trying a few different combinations of Dumble's switching schemes to see which ones I like best.

BTW, where did you mount the 220k grid resistor (return from tank)? I see it on your schematic but can't locate it on your board.

The tweaks are mostly in the tone stack area. I'm going to be trying a few different combinations of Dumble's switching schemes to see which ones I like best.

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I did the same thing on my personnal amp. The treble and mid caps have three different settings available.

BTW, where did you mount the 220k grid resistor (return from tank)? I see it on your schematic but can't locate it on your board.

Thanks,
Norm

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Hey Norm, you discovered the missing component on the board. When I designed that version I forgot to add it to the board so I ended up putting it right at the RCA jack for the reverb return. I have since corrected this devine screw- up in later boards.

I just drilled up 8 new boards of two different designs that I will be using in a set of amps I am currrently building. The first three amps of this set are a 20 and 50 watt that are similar to the previous amps I have built and the third is a 50 watt amp with a few (LOT) more bells and whistles.

One minor wiring problem on first fire-up. (Had to reverse the OT wires.) After I fixed that, the amp just sang! I dropped it off at Loren's today and he's grinning from ear to ear. Hmmm...I wonder what I should build next?

One minor wiring problem on first fire-up. (Had to reverse the OT wires.) After I fixed that, the amp just sang! I dropped it off at Loren's today and he's grinning from ear to ear. Hmmm...I wonder what I should build next?

Reverb came out pretty sweet. I used a 1Meg pot (since I didn't have any 2Megs lying around) so it's very subtle, but Loren uses very little reverb anyway. It does act a little strange past 2 o'clock...like a boost circuit, but as I said, Loren doesn't use much reverb.

After he plays it for a week or so, I'm going to get it back, install the foot switch relays, and put in the correct pot value.

Gary - Your site has been a major inspiration for me. I especially like the way you mounted the relays to the board...makes for short elegant connections to critical tone circuits. This time around I'm just using a Weber channel switch board, but as you can see, I left plenty of room on the board for relays.

Thanks,
Norm

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Normster,

how did you wire the Weber relay board to the switch - I am confused since it says it should connect the tip to the ring and neither of them should be grounded. Do I need an isolated stereo jack to do this?